"Bean put it simply: Forward guidance “is intended primarily to
clarify our reaction function.” By reaction function he meant a
description of how the policy interest rate will react to economic
variables; in other words, it’s a monetary policy rule. Bean further
clarified that forward guidance at the BoE is not, as some have
suggested, a statement that the policy interest rate will be lower in
the future than would be appropriate when the future arrives. The
intention is not “to inject additional stimulus by pre-committing to a
time-inconsistent ‘longer for longer’ policy path,” Bean said.

For the Jackson Hole regulars Bean emphasized that forward guidance
at the Bank of England is not what Michael Woodford proposed in a paper
at last year’s Jackson Hole conference. Woodford’s widely cited paper
called for central banks that are at the zero lower bound for the
interest rate to commit to keeping the interest rate at zero well into
the future and importantly well beyond the time when economic conditions
would call for a rate above zero. Woodford argued that such a
commitment on future short rates is needed to get long term interest
rates down.

In a separate session at the conference, Frank Smets said essentially
the same thing as Bean about the new forward guidance at the ECB,
explaining that “We are just trying to be transparent about our policy
intentions.” He also emphasized the difference with the Woodford paper
of last year."

Not so the Fed:

"At least as described by Bean and Smets, BoE and ECB forward guidance is
quite different from Fed forward guidance, which has important elements
of Woodford’s proposal. The Fed’s policy calls for keeping the interest
rate at zero until the unemployment rate gets down to 6.5%. But by that
time the best guess of the Fed’s reaction function, based on paper by Janet Yellen, would call for a rate above zero. So there’s the inconsistency that Bean said the BoE wants to avoid."